1. Field of the Invention
The present invention relates to a method of preserving rubber products. In detail, the present invention relates to a method of preserving rubber products which is characterized in that the rubber products are sealed in a container having gas barrier properties, together with an oxygen absorbent which requires no moisture for absorbing an oxygen and a dehydrating agent.
2. Description of the Related Art
An elastomeric plastic used for rubber products is, for example, a natural rubber and a synthetic rubber, such as a butadiene synthetic rubber, an olefin synthetic rubber, a polysulfide rubber, a fluororubber, an urethane rubber, a silicone rubber and an acrylic rubber, etc, and most of which are diene polymer. Since these diene polymer rubbers have a ultra conjugated bond in structure, a hydrogen in a methylene group adjacent to a double bond is highly reactive, and is easy to be oxidized, and rubber products using these rubbers are easy to be deteriorated while storage.
For example, in case that a rubber band is stood in air for several years, it is glued, and it is easy to cut and the surface of it turns to fishskin, and it turned not to be tolerant for use. Further, rubber products of a natural rubber series are easily decomposited by the operation of the microorganisms. This is because of a rubber decomposition enzyme secreted by microorganisms, such as a hydrolase and an oxygenase, etc, and there is a case that the secretion relates to a generation of a bad smell. Further, adhesion of a metabolized sticky substance by organisms (bacteria, etc.) can be a problem in appearance. As microorganisms are generally have high water demand, this influence causes a problem under circumstances of much moisture.
Further, in sealing products of an O-ring, etc., decreases elasticity or strength with progress of aging, and the sufficient sealing properties would not be obtained. In medical goods represented by a surgical glove, adherence properties to a hand decreases or it becomes easy to be torn with deterioration of elasticity caused by the aging. Further, in rubber products, such as rollers, materials of rubber-soled shoes, materials of cushion, sports goods and toys, the elasticity required is lost with aging of the rubber, and the original object could not be achieved.
In order to improve such aging properties of the rubber products, recently, several technique that anti-aging agents, anti-bacterial and anti-molding agent are added have been practiced. However, the aging of the rubber products are mainly caused by the oxidative effects, and amines, phenols, a peroxide decomposer are said to be adequate for an antioxidant, however, many of these anti-aging agents have susceptibility of discoloration and polluting properties, a problem of appearance properties decreasing has been pointed out. Further, in case of an anti-bacterial agent and an anti-mold agent, it is necessary to consider the safety by the toxicity.
Furthermore, the effects of these additives are not necessarily guaranteed to be stable over a long term. Even rubber products in which anti-aging agents, anti-bacterial agent and anti-mold agents are added, when they are put into severe circumstances of a high temperature and humidity even for a short time or they are stored even in the air at room temperature for a long time, there is a case that the rubber is oxidized, and the discoloration occurs or the physical properties decrease, and microorganisms germinate by the moisture, and the rubber was decomposed to become those which could not be used as rubber products.
For the purpose of preventing the deterioration of rubber products, even if moisture is removed by using a drying agent, such as a silica gel, etc, there are many cases that the physical properties decrease by an oxygen in the system, and the validity as merchandising products are extremely damaged. Therefore, although storage is tried by using a drying agent in combination with a deoxygenating agent, when deoxygenating agents in which conventional known deoxygenating agents, such as iron powder, sulfite, catechol, ascorbic acid are used as a main component are used, the oxygen absorption property decreases at inter course and the deoxygenation could not sufficiently performed, the decrease in physical properties of the rubber products occur, and could not necessarily preserve in good.
As mentioned above, the actual facts are that there has been no simple preservation method of rubber products until this time.